INVESTMENTS - Schedule of Investment Securities' Gross Unrealized Losses and Fair Value by Investment Category (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Available-for-sale debt securities:
Available-for-sale debt securities, Less than 12 months, Fair value	$ 4,239,496	$ 3,510,536
Available-for-sale debt securities, Less than 12 months, Unrealized loss	290,410	56,088
Available-for-sale debt securities, 12 months or longer, Fair value	1,005,908	550,108
Available-for-sale debt securities, 12 months or longer, Unrealized loss	120,917	23,109
Available-for-sale debt securities, Total, Fair value	5,245,404	4,060,644
Available-for-sale debt securities, Total, Unrealized loss	411,327	79,197
CMO
Available-for-sale debt securities:
Available-for-sale debt securities, Less than 12 months, Fair value	356,589	411,347
Available-for-sale debt securities, Less than 12 months, Unrealized loss	19,874	12,730
Available-for-sale debt securities, 12 months or longer, Fair value	177,496	35,638
Available-for-sale debt securities, 12 months or longer, Unrealized loss	24,373	1,903
Available-for-sale debt securities, Total, Fair value	534,085	446,985
Available-for-sale debt securities, Total, Unrealized loss	44,247	14,633
FNMA MBS
Available-for-sale debt securities:
Available-for-sale debt securities, Less than 12 months, Fair value	3,765,435	3,018,606
Available-for-sale debt securities, Less than 12 months, Unrealized loss	264,082	41,021
Available-for-sale debt securities, 12 months or longer, Fair value	652,705	356,665
Available-for-sale debt securities, 12 months or longer, Unrealized loss	72,677	12,772
Available-for-sale debt securities, Total, Fair value	4,418,140	3,375,271
Available-for-sale debt securities, Total, Unrealized loss	336,759	53,793
FHLMC MBS
Available-for-sale debt securities:
Available-for-sale debt securities, Less than 12 months, Fair value	70,215	11,227
Available-for-sale debt securities, Less than 12 months, Unrealized loss	2,064	348
Available-for-sale debt securities, 12 months or longer, Fair value	9,168	1,917
Available-for-sale debt securities, 12 months or longer, Unrealized loss	1,319	168
Available-for-sale debt securities, Total, Fair value	79,383	13,144
Available-for-sale debt securities, Total, Unrealized loss	3,383	516
GNMA MBS
Available-for-sale debt securities:
Available-for-sale debt securities, Less than 12 months, Fair value	8,377	4,847
Available-for-sale debt securities, Less than 12 months, Unrealized loss	212	71
Available-for-sale debt securities, 12 months or longer, Fair value	2,023	0
Available-for-sale debt securities, 12 months or longer, Unrealized loss	184	0
Available-for-sale debt securities, Total, Fair value	10,400	4,847
Available-for-sale debt securities, Total, Unrealized loss	396	71
GSE agency notes
Available-for-sale debt securities:
Available-for-sale debt securities, Less than 12 months, Fair value	38,880	64,509
Available-for-sale debt securities, Less than 12 months, Unrealized loss	4,178	1,918
Available-for-sale debt securities, 12 months or longer, Fair value	164,516	155,888
Available-for-sale debt securities, 12 months or longer, Unrealized loss	22,364	8,266
Available-for-sale debt securities, Total, Fair value	203,396	220,397
Available-for-sale debt securities, Total, Unrealized loss	$ 26,542	$ 10,184

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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